<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    
</body>
<script>
    let strl='x'.padStart(5,'ab');
    console.log(strl);//'ababx'

    let str2='x'.padStart(4,'ab');
    console.log(str2);//'abax'

    let str3='x'.padStart(5,'ab');
    console.log(str3);//'xabab'

    let str4='x'.padStart(4,'ab');
    console.log(str4);//'xaba'

</script>
</html>